1 Center for Care Delivery and Outcomes Research, Minneapolis VA Health Care System, Minneapolis, MN; Department of Medicine, University of Minnesota Medical School, Minneapolis, MN. Electronic address: [email protected].
2 Center for Care Delivery and Outcomes Research, Minneapolis VA Health Care System, Minneapolis, MN; Section of Pulmonary and Critical Care, Minneapolis VA Health Care System, Minneapolis, MN; Department of Medicine, University of Minnesota Medical School, Minneapolis, MN.